Field of the Invention
The present invention relates to an organic light emitting diode display device that includes a light-scattering layer having a pattern applied thereto.
Description of the Prior Art
Organic light emitting diode display devices, which are self-light emitting display devices, may be made lighter and slimmer since they do not need separate light sources, as opposed to liquid crystal display devices. Furthermore, organic light emitting diode display devices have been studied as next-generation display devices thanks to their excellent implementation of color, response speed, viewing angle, and contrast ratio (CR), as well as advantages in power consumption by means of low-voltage operation.
Light emitted from an organic light emitting layer of an organic light emitting diode display device passes through multiple components of the organic light emitting diode display device and exits from the organic light emitting diode display device. However, a part of the light emitted from the organic light emitting layer is confined in the organic light emitting diode display device without being extracted therefrom. Accordingly, the light extraction efficiency of an organic light emitting diode display device has come into question.
Particularly, in a bottom-emission type organic light emitting diode display device among organic light emitting diode display devices, light confined in the organic light emitting diode display device due to total-reflection or light-absorption by an anode electrode accounts for as much as about 50% of light emitted from an organic light emitting layer, and light confined in the organic light emitting diode display device due to total-reflection or light-absorption by a substrate accounts for as much as about 30% of the light emitted from the organic light emitting layer. As described above, about 80% of the light emitted from the organic light emitting layer is confined in the organic light emitting diode display device, and only about 20% thereof is extracted from the organic light emitting diode display device, which leads to a very low light-extraction efficiency.
In order to enhance the light extraction efficiency of such an organic light emitting diode display device, a method for attaching a micro lens array (MLA) to the outside of a substrate of an organic light emitting diode display device or a method for forming micro lenses on an overcoat layer of an organic light emitting diode display device has been developed.
However, by applying a micro lens array or micro lenses, light directed toward an adjacent sub-pixel among light emitted from an organic light emitting element travels along an overcoat layer on account of an additional inclined surface generated by the micro lenses disposed on the edge of an emissive area and reaches the adjacent sub-pixel emitting light having a different color to cause a light leakage phenomenon.